There’s no Gesture section at all on iOS, checked both in the in-app settings as well as the app settings in the Settings app. Honestly the settings page is a bit of a travesty in terms of UX design. There’s a “Theme” section that when clicked, takes you to an on/off switch for “Use system theme” and nothing else. Why not just have the switch directly on the main settings page? Maybe under its own subsection, but not a completely different page?

I installed Firefox on my Pixel 6 (work phone, pretty much only use it for Teams and two authenticator apps), and it’s a completely different experience.

The iOS version wastes a lot of space, and there’s a lot less room for customisation.

On Android the setting was under Settings > Customise which by itself has a decent amount of settings.

And the iOS settings page, slightly scrolled down to hide my email address, looks like this (imgur link).